ee: 
370 Mr. M. Ponton on certain Laws | 
Taste I.—Elements of Calculation. 
The media arranged according to the value of loge. 
Media | 7.8ss50)se log e. a, n.| loge, Gn 
P. Nitrate of bismuth ...... 0°1185050| 0°009597 es O°1214201 aR Re, 
Water, No. 1, T. 18°75... 
INSGIIG ACIA 5... cchscesceosens 
Muriate of lime............ 
Muriatic acid, T. 18°°6 ... 
Sol. of Potash, T. 21°°5... 
Solution of soda ......... 
Solution of potash, T. 16°. 
Sulphuric acid, T. 186... 
iP. 
F 
Ee 
Es 
Up 
Pp: 
Pp, 
Pp. 
Pe 
Ps 
Re 
lis 
B 
P. 
Ee 
Le 
Meg 
P. 
F. 
P: 
Py 
BR: 
F. 
R. 
aa 
P. 
P. 
P. 
Pe 
Pi 
P. 
Es 
F. 
PF. 
ine 
R. 
R. 
FP) 
F. 
Ee 
F. 
F. 
¥. 
FF. 
F. 
R. 
R. 
R. 
R. 
Calc-spar ex. ray ......... 0°1661054| 07008120} ,.. |0°1695691) 0'002824 
Oilofeassia, No. 3,T.22°°5.| 0°1671802] 0°04.9533] 3°4| 0°1966605) 0006945 
Oil of sassafras, T.20%'9 ..| 0°16805 34) 0'023053] 2°7| 0°18c0982) 0'005144 
Oil of anise, T. 20°9......| 07168338 1| 0°030529] 2°38] 0°184.7136| 0°006356 
Oil of cassia, T.14° ...... 0°1688690) 0048800] 3°5| 0°1982254| 0°006483 
Oil of anise, T. 15°r...... 0°1695285| 0°030191| 2°8| 0°185 74.98] 0°c06297 
Oil of cassia, T. 10° ...... 0°1695982| 07048723] 3°2] 0°1978781) 0°007803 
Oil of anise, T, 13°25 ...] 071698189] 0°029579| 2°38] 0°1857218] 0006165 
Creosote ..... REE seeeee| 0°1699152| 07022836) 2°5| 0°18 13 500] 0005855 
Crown-glass No. 13 «.-...|0°1755898) 0°011225] 1°9| 0°1800728] 0°004.550 
Crown-glass No.9 ...... 0°1759127| 0°011384] 1*9] 0°1804622| 0'004615 
Rock-salt .....e0ee0+e+00] O°1771542| 0°01 5460] 2°2| 0°1842930] 0°004.942 
Arragonite, Ist axis ...... 0°1785369| 0°008 122} 1°g| 0° 1817994} 0'003291 
Quartz O.ray.......0..... + |0°1814768} 0009365] 1°7| 0°184.7752| o'004.501 
Bisulphide of carbon......] 0°1819878| 0°038772| 2°5| 0°202 1429] 0°009949 
Crown-glass M.........++...| 0°1828213| 0°01 3003] 2°0| 0°1883987| 0004857 
Quartz eX. ray «s..........| 0°1838 501} 0009541] 1°7| 0°1872281] 0004586 
Flint-glass No. 3 ......... 0°1915881) 0'018721| 2°2| 0°2005423] 0005986 
Flint-glass No. 30 ......... 0°19618 52) 0020178] 2°2| 0'2059514| 0'006450 
Flint-glass No. 23 (2) 0°1967997| 0°020402) 2°2| 0'2066932) 0°006518 | ¥ 
Flint-glass No. 23 (1) ...| 0°1968160| 0°020382) 2°2| 0°2066932| 0'006518 
Flint-glass No. 13 ......... 0°1970545| 07020502) 2"1| 0°2066058] 0'007080 
Topaz, 2nd axis............] 0'2004488| 0008465] 1°7| 0°2035624| o'c04069 
Topaz, 3rd axis ............ 0°2010442| 0°008421| 1°7] 0°204.1424| 0°004051 
Topaz, 1st axis ............ 0°2029670) 0'008466) 1°8] 0°206342 5] 0°003735 
Cale-spar O. ray ......... 0°208 1261) 0°014107] 1°9| 02142084] 0°005719 
R. Arragonite, 3rd axis ...... 0°2 148137) 0'013062! 1°9| 0°2205295] 0°005297 
R. Arragonite, 2nd axis...... 0°2 156888) 0°013 330} 20] 0°2218703] 0'004971 
F= Fraunhofer. P= Powell. R = Rudberg, 
Oil of turpentine, T.10°°6.. 
Water, No. 2, T. 18°75...| 0°1185793] 0°009645} ... | 0°1212442| 0°005087 
Mister. SP te Gio. tacdyene 0°118707 1) 0°0098 36) 2°0| 0°1223208] 0003694 
Muriate of zine ............ 0°1190925| 0°012365 
Subacetate of lead....... +] 0°1199078] 0°009 548} 1°8] 071230654! o'c04 192 
Nitrate of mercury ......]0°1210345| O'O108g1! .., | 0°1246282| o'004806 
Sulphate of soda .......-. 0°1210587| 0009894] 1°6] 0°1238184] 07005206 
Muriate of baryta ......... 0°1213789| 0°009615| 2°6] 0°1257358] 0'002316 
Superacetate of lead ...... 0°1221380} 0°010067| 1°9| 0°12 56868} 0'004083 
Nitrate of potash ......... 0°1225076| 0°01 1004] 2°4| 0°1273767| 0'002970 
Sulphate of magnesia ...| 071225266) 0009738] 1°4| 0°1246065| 0°006206 
Nitrate of lead ...... seeeee] 071227524] 0°010397| 1°8| 0° 1262004] 0°004.583 
Muriate of ammonia...... 0°1240384| 07010655] 1°38] 0°1275798] 0°004.701 
Alcohol, Ti27°°6) 222.5%: 0°1288364| 0°0093638} 1°7| 0°1317 568] 0'004.504. 
Pyroligneous acid ...... +++] 0°13. 15513] O°0103 12] 2°0] 0°13.54593| 0°003869 
0°1370585| o’014199 
0°1389150| 0°012103 
0°1392094| 07013901 
0°1392960] o'01 1002 
0°1396349| o'o12410 
0°1398999| 0°011513 
0°1 50204 5| 07009301 
0°1585949) 0°013758 
2°1| 0°1427913] 0'004907 
19] 01433528] o'004g IT 
1°4| 0°1422945| 0'008862 
1°7| 0°1428138] 0°005287 
1°6| 0°1432346} 0'006549 
1°4| 0°5424568] 0°007341 
1'0] 0°1502375] 0'009259 
2°1|0°1644359] 0'004751 
* Mean of two observations. 
Note.—The elements log en, an, and n are the three from which the 
indices in Table VI. are caleulated. The elements loge and a are those 
from which the wave-lengths in Table III. are calculated. 
